The installation and maintenance of outdoor electric power supply lines includes passing cables over roads, rails, bodies of water and other structures. In the event that such cables break or fall unintentionally, the result is often serious physical damage, risk of electrocution, and emergency closure of the road or railway. Of course the same concerns apply to overhead communication cables, telephone lines, cable television cables etc.
To prevent such occurrences, electrical workers erect temporary frames on both sides of a road for example. The temporary frames are made of vertical utility poles with horizontal poles or horizontal wires to catch any falling cables and prevent the cables from touching the road surface. Road traffic can continue without interruption during work on the overhead cables that cross the road since the temporary frames serve to catch any cables that break or fall before they can touch the road surface or any vehicles.
Constructing and removing temporary frames made of utility poles requires significant time, lifting equipment and labour. Workers building temporary frames are exposed to falling hazards and the risk of accidentally contacting the electric cables that pass over the frames as they are being assembled and disassembled. The time and effort required to erect and remove temporary frames can often be out of proportion to the work on electric cables themselves.
Prior art devices also exist to lift cables temporarily during replacement of utility pole insulators or other work on cables, for example as shown in U.S. Pat. No. 5,076,449 to Clutter and U.S. Pat. No. 4,721,213 to Eitel among many others.
Features that distinguish the present invention from the background art will be apparent from review of the disclosure, drawings and description of the invention presented below.